title: Molecular Genetic Diversity of Major Indian Rice Cultivars over Decadal Periods.
abstract: Genetic diversity in representative sets of high yielding varieties of rice released in India between 1970 and 2010 was studied at molecular level employing hypervariable microsatellite markers. Of 64 rice SSR primer pairs studied, 52 showed polymorphism, when screened in 100 rice genotypes. A total of 184 alleles was identified averaging 3.63 alleles per locus. Cluster analysis clearly grouped the 100 genotypes into their respective decadal periods i.e., 1970s, 1980s, 1990s and 2000s. The trend of diversity over the decadal periods estimated based on the number of alleles (Na), allelic richness (Rs), Nei's genetic diversity index (He), observed heterozygosity (Ho) and polymorphism information content (PIC) revealed increase of diversity over the periods in year of releasewise and longevitywise classification of rice varieties. Analysis of molecular variance (AMOVA) suggested more variation in within the decadal periods than among the decades. Pairwise comparison of population differentiation (Fst) among decadal periods showed significant difference between all the pairs except a few. Analysis of trends of appearing and disappearing alleles over decadal periods showed an increase in the appearance of alleles and decrease in disappearance in both the categories of varieties. It was obvious from the present findings, that genetic diversity was progressively on the rise in the varieties released during the decadal periods, between 1970s and 2000s.
authors.affiliation: Institute of Biotechnology, Acharya NG Ranga Agricultural University, Rajendranagar, Hyderabad, Andhra Pradesh, India.
authors.forename: Gangaprasad
authors.initials: G
authors.lastname: Choudhary
authors.forename: Nagireddy
authors.initials: N
authors.lastname: Ranjitkumar
authors.forename: Malathi
authors.initials: M
authors.lastname: Surapaneni
authors.forename: Dondapati Annekitty
authors.initials: DA
authors.lastname: Deborah
authors.forename: Abhilash
authors.initials: A
authors.lastname: Vipparla
authors.forename: Ghanta
authors.initials: G
authors.lastname: Anuradha
authors.forename: Ebrahimali Abubacker
authors.initials: EA
authors.lastname: Siddiq
authors.forename: Lakshminarayana Reddy
authors.initials: LR
authors.lastname: Vemireddy
mesh_terms: D000483:Alleles; D018744:DNA, Plant / Q000302:isolation & purification / Q000378:metabolism; D056426:Genetic Loci; D014644:Genetic Variation; D005838:Genotype; D006579:Heterozygote; D007194:India; D018895:Microsatellite Repeats / Q000235:genetics; D012275:Oryza / Q000235:genetics*; D011110:Polymorphism, Genetic
chemical_list: D018744:DNA, Plant